17 research outputs found

    Simultaneous measurements of X-rays and electrons during a pulsating aurora

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    Doppler-shifted auroral H β emission: a comparison between observations and calculations

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    Two sounding rockets equipped with photometers and particle detectors have been flown into proton auroras. The measured altitude dependence of the proton flux is compared with calculations based upon known energy-range relations for protons in air. Expressions suitable for numerical calculations of Doppler profiles at arbitrary angles to the geomagnetic field and at different heights within an aurora are developed. Profiles due to some typical proton spectra have been calculated and it is shown that altitude profiles at some wavelengths are more sensitive to the shape of the proton spectrum than are profiles at other wavelengths. Variations in the <i>H&#x03B2;</i> Doppler profile versus height for several angles with the magnetic field is studied. Profiles, as generated by the actually measured protons in the energy range 1 keV to 1 MeV, have been calculated and are compared with direct optical measurements made by ground and rocket photometers. The rocket photometers took measurements at different wavelengths within the Doppler profile. The correspondence between calculations and measurements is generally good. The total <i>H&#x03B2;</i> is calculated and fair agreement with the measured intensity is found

    Doppler-shifted auroral H &#x03b2; emission: a comparison between observations and calculations

    No full text
    Two sounding rockets equipped with photometers and particle detectors have been flown into proton auroras. The measured altitude dependence of the proton flux is compared with calculations based upon known energy-range relations for protons in air. Expressions suitable for numerical calculations of Doppler profiles at arbitrary angles to the geomagnetic field and at different heights within an aurora are developed. Profiles due to some typical proton spectra have been calculated and it is shown that altitude profiles at some wavelengths are more sensitive to the shape of the proton spectrum than are profiles at other wavelengths. Variations in the H&#x03B2; Doppler profile versus height for several angles with the magnetic field is studied. Profiles, as generated by the actually measured protons in the energy range 1 keV to 1 MeV, have been calculated and are compared with direct optical measurements made by ground and rocket photometers. The rocket photometers took measurements at different wavelengths within the Doppler profile. The correspondence between calculations and measurements is generally good. The total H&#x03B2; is calculated and fair agreement with the measured intensity is found

    Simultaneous measurements of X-rays and electrons during a pulsating aurora

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    The PULSAUR II rocket was launched from Andøya Rocket Range at 23.43 UT on 9 February 1994 into a pulsating aurora. In this paper we focus on the observations of precipitating electrons and auroral X-rays. By using models it is possible to deduce the electron energy spectrum from X-ray measurements. Comparisons are made between the deduced electron fluxes and the directly measured electron fluxes on the rocket. We found the shape of the observed and the deduced electron spectra to fit very well, with almost identical e-folding energies in the energy range from 10 ke V to ~60–80 ke V. For the integrated fluxes from 10.8 to 250 ke V, we found a discrepancy of 30% . By combining two models, we have found a good method of deducing the electron precipitation from X-ray measurements. The discrepancies between calculations and measurements are in the range of the uncertainties in the measurements.Key words. Ionospheric particle precipitation · Magnetospheric physics · Annual phenomena · Energetic particl

    Psychometric properties of the Norwegian translation of the Tinnitus Handicap Inventory (THI-NOR)

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    Objective: To assess the psychometric properties of a Norwegian translation of the Tinnitus Handicap Inventory (THI-NOR). Design: A survey was sent by post to patients referred with tinnitus as their main complaint to an audiology department. Patients completed a Norwegian version of the Tinnitus Handicap Inventory (THI-NOR), a Norwegian translation of two revised subscales of the Abbreviated profile of hearing aid benefit (APHAB), the General Health Questionnaire (GHQ-12) as well as questionnaires measuring coping expectancies (TOMCATS) and neuroticism (EPI). Study sample: Ninety-nine persons with tinnitus. Results: No associations were found between THI-scores or pure-tone audiometry, gender or age. The proposed subscales of the original THI were not formed by responses from responders. The total scale shows good psychometric properties. Significant correlations were found between distress as measured by the GHQ-12, coping expectancies as measured by TOMCATS and neuroticism as measured by EPI and THI scores. Conclusions: THI-NOR has psychometric properties similar to those of the Danish translation (THI-DK), from which it was adapted, and to the original THI. THI-NOR seems to be a valid measure of the impact of tinnitus on a person’s everyday life. Findings show that the suggested subscales of the questionnaire should be interpreted with caution
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